The present disclosure relates to a tantalum capacitor and a method of manufacturing the same.
A tantalum (Ta) material is a metal widely used in various industrial fields such as space and military fields, and the like, as well as electrical, mechanical, and chemical fields due to mechanical or physical properties thereof such as a high melting point, excellent flexibility and corrosion-resistance, and the like.
Since such a tantalum material may form a stable anodic oxide film, the tantalum material has been widely used as a positive electrode material of a small capacitor. Recently, in accordance with the rapid development of information technology (IT) industries such as electronic and info-communications industries, the amount of tantalum used has been rapidly increased every year.
Generally, a capacitor refers to a condenser temporarily storing electricity therein and is a component in which two flat plate electrodes insulating from each other are allowed to approach each other, while having a dielectric substance interposed therebetween, and electrical charges are charged and accumulated therein by attractive force. Such a capacitor may store electric charges and electrical fields in a space formed by two conductors, and may be used to obtain capacitance.
A tantalum capacitor using the tantalum material has a structure using an empty gap generated at the time of sintering and hardening a tantalum power and may be completed by forming a tantalum oxide (Ta2O5) on a tantalum surface using an anodic oxidation method, forming a manganese dioxide (MnO2) layer, which is an electrolyte, on the tantalum oxide serving as a dielectric substance, forming a carbon layer and a metal layer on the manganese dioxide layer to form a body, forming positive and negative electrodes on the body to mount the electrodes on a circuit board, and forming a molding part.
A tantalum capacitor according to the related art has a structure in which a terminal is exposed to the outside using an internal lead frame or without the frame in order to connect the tantalum material and an electrode to each other.
In the case of a structure using internal lead frames, a space occupied by the tantalum material in the molding part may be decreased by the internal lead frames configuring the positive and negative electrodes, and a limitation in capacitance may be caused since the capacitance is in proportion to a volume of the tantalum material.
In the case of the structure in which the terminal is exposed to the outside without the frame, since a plurality of materials in contact with the tantalum material are present, contact resistance is increased by the plurality of contact materials, such that equivalent series resistance (ESR) of the capacitor may be increased.
Further, in the case of the structure in which the terminal is exposed to the outside without the frame, since a negative electrode terminal is positioned at a side of a product, a welding distance for forming a solder needs to be secured between the tantalum material and the negative electrode terminal, such that an internal volume ratio of the tantalum material may be decreased. Therefore, the capacitance may be decreased.